Investors

News Release

REDWOOD CITY, Calif., March 7, 2013 /PRNewswire/ -- AcelRx Pharmaceuticals, Inc. (Nasdaq: ACRX), a specialty pharmaceutical company focused on the development and commercialization of innovative therapies for the treatment of acute and breakthrough pain, today announced that it will release fourth quarter 2012 financial results after market close on Tuesday, March 12, 2013. AcelRx management will host an investment-community conference call at 4:30 p.m. Eastern time (1:30 p.m. Pacific time) on March 12, 2013 to discuss the financial results and provide a corporate update.

Investors who wish to participate in the conference call may do so by dialing (800) 860-2442 for domestic callers, (866) 605-3852 for Canadian callers or (412) 858-4600 for international callers. Those interested in listening to the conference call live via the Internet may do so by visiting the Investors page of the company's website at www.acelrx.com and clicking on the webcast link on the Investor home page.

A webcast replay will be available on the AcelRx website for 90 days following the call by visiting the Investors page of the company's website at www.acelrx.com.

About AcelRx Pharmaceuticals, Inc.

AcelRx Pharmaceuticals, Inc. is a specialty pharmaceutical company focused on the development and commercialization of innovative therapies for the treatment of acute and breakthrough pain. AcelRx's lead product candidate, the ARX-01 Sufentanil NanoTab PCA System, is designed to solve the problems associated with post-operative intravenous patient-controlled analgesia which has been shown to cause harm to patients following surgery because of the side effects of morphine, the invasive IV route of delivery and the complexity of infusion pumps. ARX-01 has successfully completed two of its three planned Phase 3 clinical trials and a New Drug Application submission is planned for the third quarter of 2013. AcelRx recently completed enrollment in a Phase 2 study for ARX-04, a sufentanil formulation for the treatment of moderate-to-severe acute pain, funded through a grant from U.S. Army Medical Research and Materiel Command, and top-line results are expected in the second quarter of 2013. The company has two additional pain treatment product candidates, ARX-02 and ARX-03, which have completed Phase 2 clinical development. For additional information about AcelRx's clinical programs please visit www.acelrx.com.

Forward Looking Statements This press release contains forward-looking statements, including, but not limited to, statements related to anticipated timing of completion of AcelRx Pharmaceuticals' current clinical trials, submission of the NDA, and the therapeutic potential of AcelRx Pharmaceuticals' product candidates. These forward-looking statements are based on AcelRx Pharmaceuticals' current expectations and inherently involve significant risks and uncertainties. AcelRx Pharmaceuticals' actual results and the timing of events could differ materially from those anticipated in such forward-looking statements as a result of these risks and uncertainties, which include, without limitation, risks related to: the success, cost and timing of AcelRx Pharmaceuticals' product development activities and clinical trials; its ability to obtain sufficient financing to complete development and registration of its product candidates in the United States and Europe; its ability to obtain and maintain regulatory approvals of its product candidates; the market potential for its product candidates; and other risks detailed in the "Risk Factors" and elsewhere in AcelRx Pharmaceuticals' U.S. Securities and Exchange Commission filings, including its Current Report on Form 8-K filed with the SEC on December 7, 2012. AcelRx Pharmaceuticals undertakes no duty or obligation to update any forward-looking statements contained in this release as a result of new information, future events or changes in its expectations.